Building automation and control refers to the use of computer and information technology to control building systems, such as lighting, HVAC, audio-visual, smoke detection, security, and shading, among other systems. Using specialized hardware, building devices can be monitored and controlled automatically. Although building automation has been available at some level of sophistication for some time, it steadily becomes more practical, both from a technological and cost perspective. This is due in part to the rapid advancement of information technology.
A sophisticated building automation system might include sensor devices (e.g., of temperature, of light, of motion, of switch actuation, etc.), actor devices (e.g., lamps, climate control, motorized window shades, etc.), and, in some cases, separate controller devices (e.g., a general-purpose personal computer, a dedicated automation controller, etc.). The actor devices act upon the information gathered and transmitted by the sensor devices. For example, a sensor detects motion, propagates this information such that a light module receives it, which module turns on electrical current to a light bulb as a result. The system might also include a human-machine interface device that enables an occupant of the building to interact with the system. The interface can be a specialized terminal or an application (“app”) running on a smartphone or tablet computer. The various system devices communicate over dedicated wiring, or over a wired network, or wirelessly, using one or more protocols.
Many building automation systems are based on peer-to-peer network architectures that include the sensor and actor devices. In a peer-to-peer network, sensor devices transmit information such that actor devices can act upon the information transmitted and without the need for an intermediary controller.
There are various classes of peer-to-peer automation systems in the prior art. In a first building automation system in the prior art, depicted in FIG. 1A, each sensor device communicates directly with a particular actor or actors. The actor device does not analyze the information it gets; rather, it merely responds to it. The entire logic is in the sensor device, in terms of which actor or actors should the sensor device trigger, for how long, on what condition, and so on. A particular example of this class of automation systems is based on Z-Wave™ radio technology, widely used in building installations, in which the sensors devices are thermostats, motion sensors, and wall switches, and the actor devices are typically actuators that affect the flow of electrical current, such as to a light bulb and so on.
In a second building automation system in the prior art, depicted in FIG. 1B, each sensor device broadcasts its signal, but does not know who the recipient of the signal is. Each actor device monitoring for signals that are being broadcast by sensor devices is programmed to listen to specific events from specific sensor devices, which identify themselves by also broadcasting their source addresses. Most of the control logic in this class of automation systems is in the actor device, in contrast to the sensor device as in the system depicted in FIG. 1A. A particular example of this class of automation systems is based on EnOcean™ radio technology, in which the wireless sensor is powered by the physical force of pushing a button or by another energy-harvesting approach, although the sensor devices in other automation systems in this class can be battery powered.